Process for removing spots from clothes in laundry machines with a vertical shaft

ABSTRACT

A process for removing spots from clothes in laundry machines with a vertical shaft comprising the steps of: a—supplying a washing liquid to a load of soiled clothes inside a perforated basket ( 2 ) for containing clothes and provided internal to a tub ( 1 ) that is supplied with washing liquid until reaching a predetermined level, which is substantially lower than the lowest laundering level and compatible with the load of clothes; b—submitting this load of clothes to at least one agitation period during a certain first agitation time interval; c—maintaining said load of clothes at rest after a respective agitation period has elapsed and during a predetermined first rest time interval, sufficient for the temperature of the washing liquid to reach a value necessary to allow the activation of at least one of the enzymatic and bleaching functions of the washing liquid; d—submitting the load of clothes to a subsequent agitation period during a certain second agitation time interval, sufficient to provide a certain cleaning of the load of clothes, but insufficient to cause a relevant drop in the temperature reached by the washing liquid.

FIELD OF THE INVENTION

The present invention refers to a process for removing spots from clothes in laundry machines with a vertical shaft and which presents a perforated basket to contain the clothes to be laundered.

BACKGROUND OF THE INVENTION

In conventional laundry machines with a vertical shaft and with a laundering system by agitation, the laundering cycle has a water heating system usually provided in a bottom portion of a tub, inside which is provided the perforated basket, said water heating system containing a resistance of about 1500 W, which actuates during the soaking step of the laundering cycle to increase the temperature to about 45° C.

Among the conventional constructions for laundry machines are those with the capacity to wash 5 kg of dry clothes and those with the capacity to wash 7 kg of dry clothes. These machines generally present laundering programs, each for a determined intensity of laundering action, which can be selected according to the amount of soil in the clothes to be laundered. The dirtier the clothes the more intense should be the laundering program to be selected.

These constructions further present a water level selector, which allows adjusting the quantity of water according to the quantity of clothes to be laundered. Although the known laundering programs lead to good results in cleaning the common soil from the clothes, the quality of the spot removing operation is not the desired one.

The quality of the soil-spot removal from a load of clothes in a laundry machine depends on four factors: the chemical action obtained as a function of the characteristics of the detergent used; the mechanical action corresponding to the transfer of movement from the mechanical parts of the laundry machine to the load of clothes being laundered; the thermal action related to the heating of the washing liquid and which is effected by the electrical resistance of the laundry machine; and the time action related to the duration of each laundering program.

Among these factors, the thermal action is the one that allows improving the spot removal. However, the known constructions cannot increase the temperature of the washing water as a function of the aspects presented below.

The laundry machines with a vertical shaft require a large quantity of water to effect the laundering of clothes. The high energy consumption and mainly the long time needed to heat this volume of water by means of the electrical resistance available in these machines make the use of temperatures above 45° C. impracticable.

On the other hand, the use of a more powerful resistance to reduce the heating time and increase the temperature of the volume of water requires a special electrical installation in residences, making this solution unfeasible.

OBJECTS OF THE INVENTION

Thus, it is an object of the present invention to provide a process for laundering clothes, which allows an improved spot removal from the clothes to be laundered.

Another object of the present invention is to present a process as mentioned above, which allows, within the existing limitations of installation and energetic consumption, to obtain temperatures for laundering clothes higher than those reached in the existing laundry machines of household use, without requiring to modify the capacity of the resistance presently used in the available laundry machines.

SUMMARY OF THE INVENTION

These and other objects are achieved by a process for removing spots from clothes in laundry machines with a vertical shaft, of the type comprising a tub for containing a washing liquid in at least one laundering level, and a perforated basket for containing clothes and provided internal to the tub, said process comprising the steps of: a—supplying a washing liquid to a load of soiled clothes contained inside the perforated basket until reaching a predetermined level that is substantially lower than the lowest laundering level and compatible with the load of clothes; b—submitting the load of clothes immersed in the washing liquid to at least one agitation period during a certain first agitation time interval; c—maintaining the load of clothes immersed in the washing liquid at rest after a respective agitation period has elapsed and during a predetermined first rest time interval sufficient for the temperature of the washing liquid to reach a value necessary to allow the activation of at least one of the enzymatic and bleaching functions of the washing liquid; d—submitting the load of clothes immersed in the washing liquid to a subsequent agitation period during a certain second agitation time interval, which is sufficient to provide a certain cleaning of the load of clothes, but insufficient to cause a relevant drop in the temperature reached by the washing liquid; and e—extracting the washing liquid from the load of clothes.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be described below, with reference to the enclosed drawings, in which:

FIG. 1 illustrates, schematically and in a vertical longitudinal sectional view, a laundry machine with a vertical shaft, presenting the predetermined level (L1) of washing liquid for the process of the present invention, and a minimum level (L2) of washing liquid for a conventional laundering;

FIG. 2 illustrates, graphically, the temperature versus time relation of different steps in a form of carrying out the process of the present invention; and

FIG. 3 illustrates, graphically, the temperature versus time relation of different steps of another form of carrying out the process of the present invention.

DESCRIPTION OF THE ILLUSTRATED EMBODIMENT

The present invention will be described in relation to a laundry machine of the type illustrated in FIG. 1 and which comprises a tub 1 for containing washing liquid, said tub 1 being tubular and cylindrical and provided inside a non-illustrated cabinet, inside which is concentrically mounted a perforated basket 2, for containing clothes to be laundered, of the tubular cylindrical type with a vertical shaft and which is in selective fluid communication with a non-illustrated water supply source.

According to the present invention, the water supply source feeds water to the tub 1 in a predetermined level L1, which is calculated to be compatible with a load of soiled clothes corresponding to about 30% the nominal load of clothes which requires, for example, the lowest laundering level L2 defined for that laundry machine. The predetermined level L1 is calculated so that the whole load of soiled clothes remains substantially immersed in the washing liquid. The present invention provides a spot removing process comprising a first step, in which there is supplied a washing liquid, generally comprising water and a laundering detergent, to a load of soiled clothes contained within the perforated basket 2, until reaching the predetermined level L1, which is substantially lower than the lowest laundering level L2.

According to the present invention, once the predetermined level L1 has been reached, there is 10 started at least one agitation period of the load of soiled clothes immersed in the washing liquid, during which period the clothes are agitated without water heating, for example maintaining said water at room temperature, and during a first agitation time 15 interval sufficient for contacting the entire load of clothes with the washing liquid.

In a form of carrying out the present invention (FIG. 2), this first agitation time interval is of about 7 minutes.

Upon completion of said agitation period, the process of the present invention foresees a subsequent step, in which the load of soiled clothes immersed in the washing liquid is submitted to a respective resting condition, while a heating system for the washing liquid of the present laundry machine is activated.

The resting condition of this step is maintained during a predetermined first rest time interval, in order that the temperature of the washing liquid reaches a value necessary to allow the activation of at least one of the enzymatic and bleaching functions of the washing liquid.

In a form of carrying out the present invention, the duration of this resting condition time interval is calculated so that the temperature reaches about 40° C.-45° C., preferably 45° C., which temperature generally activates the enzymatic function of the known detergents that form the washing liquid together with the water supplied to the tub. Said time interval is of the order of 20 minutes.

Upon completion of this resting step of the load of clothes, the latter is submitted to a subsequent agitation period during a second agitation time interval, which is calculated to be sufficient to provide a certain cleaning of the load of clothes, but insufficient to cause a relevant drop in the temperature reached by the washing liquid. During the second agitation time interval, the maintained temperature assures maintenance of the activation of the washing liquid functions, as previously discussed. This second time interval is, for example, equal to the time interval of the first agitation time interval and calculated to be about 7 minutes.

According to the present invention, after a preceding agitation period, the washing liquid is submitted to a subsequent resting step during a predetermined second rest time interval, so that the heating system, operating since the previous rest time, increases the temperature of the washing liquid to a value necessary to activate at least the other of said washing liquid functions, such as the bleaching function thereof, which has not been achieved with the temperature reached at the previous rest time interval.

In a form of carrying out the present invention, the duration of this subsequent resting condition time interval is calculated so that the temperature reaches about 60° C.-65° C., preferably 65° C., which temperature is desirable to generally activate the bleaching function of the known detergents that form the washing liquid jointly with the water supplied to the tub 1. The duration of said time interval is, for example, that of the previous resting condition i.e., of the order of 20 minutes.

In this embodiment, after the time interval of this last resting period has elapsed, the present process comprises a respective subsequent agitation period, which is calculated so that the reached temperature remains substantially unaltered, producing in this period the bleaching effect. This subsequent agitation period occurs during a respective third time interval sufficient to provide a certain cleaning of the load of clothes, but insufficient to cause a relevant drop in the temperature reached by the washing liquid.

According to the present invention, the third time interval is, for example, substantially equal to that of the previous agitation periods i.e., of about 7 minutes.

With the process for removing spots from clothes in a laundry machine of the present invention it is possible to reach higher laundering temperatures in the laundry machines with a vertical shaft, without modifying the heating system thereof i.e., with the same resistance conventionally used in these systems.

In an option of carrying out the present invention, after the last agitation period with the washing liquid being heated at about 65° C., the present process has the final step of extracting the washing liquid from the load of clothes, for example by draining or spinning, as described below.

In the constructions in which the spot removing process is a laundering process independent of the conventional laundering process of the laundry machine, after the last agitation period, for example after the second agitation period, said process foresees the step of extracting the laundering liquid with the subsequent rinsing and spinning operations, thus finishing said spot removing process.

In the constructions in which the spot removing process is a laundering step of a laundry machine laundering program, after the last agitation period of said spot removing step, there is foreseen an additional step, in which water is re-supplied to the tub, until reaching a conventional laundering level, after which the conventional laundering operation of the selected program is processed.

In another possible option of carrying out the invention, as illustrated in FIG. 3, upon completion of the agitation period with the washing liquid at the room temperature, a resting period starts, for example of about 40 minutes, which is sufficient for the washing liquid, in which the load of soiled clothes is immersed, to reach a temperature of about 65° C. At the end of the single resting-heating period, the load of clothes and the washing liquid are submitted to an agitation period under heat, as already described in relation to the procedure with reference to FIG. 2. 

1. A process for removing spots from clothes in laundry machines with a vertical shaft, comprising a tub (1) for containing a washing liquid in at least one laundering level, and a perforated basket (2) for containing clothes and provided internal to the tub (1), said process characterized in that it comprises the steps of: a—supplying a washing liquid to a load of soiled clothes contained inside the perforated basket (2) until reaching a predetermined level that is substantially lower than the lowest laundering level and compatible with the load of clothes; b—submitting the load of clothes immersed in the washing liquid to at least one agitation period during a certain first agitation time interval; c—maintaining the load of clothes immersed in the washing liquid at rest after a respective agitation period has elapsed and during a predetermined first rest time interval sufficient for the temperature of the washing liquid to reach a value necessary to allow activation of at least one of the enzymatic and bleaching functions of the washing liquid; d—submitting the load of clothes immersed in the washing liquid to a subsequent agitation period during a certain second agitation time interval, which is sufficient to provide a certain cleaning of the load of clothes, but insufficient to cause a relevant drop in the temperature reached by the washing liquid; and e—extracting the washing liquid from the load of clothes.
 2. The process as set forth in claim 1, characterized in that it includes, after step “d”, the additional steps of:—maintaining the load of clothes immersed in the washing liquid after a preceding agitation period has elapsed and during a predetermined second rest time interval, sufficient for the temperature of the washing liquid to reach a value necessary to allow activation of the other of said enzymatic and bleaching functions of the washing liquid not obtained with the temperature reached in the previous rest time interval;—submitting the load of clothes immersed in the washing liquid to another respective and subsequent agitation period during a certain third agitation time interval, sufficient to provide a certain cleaning of the load of clothes, but insufficient to cause a relevant drop in the temperature reached by the washing liquid.
 3. The process as set forth in claim 1, characterized in that it includes, after step “e”, the steps of rinsing the load of clothes and spinning the washing liquid.
 4. The process as set forth in claim 3, characterized in that it includes, after step “e”, and prior to the rinsing and spinning steps, the steps of:—supplying a determined quantity of water to the load of clothes in the perforated basket, until reaching a previously selected laundering level; and—submitting the load of clothes to the steps of a laundering process.
 5. The process as set forth in claim 1, characterized in that the temperature in the first rest time interval reaches about 40° C.-45° C.
 6. The process as set forth in claim 2, characterized in that the temperature in the second rest time interval reaches about 55° C.-65° C.
 7. The process as set forth in claim 1, characterized in that the first agitation period is carried out at room temperature.
 8. The process as set forth in claim 1, characterized in that the predetermined level is calculated for a load of soiled clothes of about 30% the nominal load of the lowest laundering level.
 9. The process as set forth in claim 8, characterized in that the agitation periods present the same duration.
 10. The process as set forth in claim 9, characterized in that the agitation periods are of the order of 7 minutes.
 11. The process as set forth in claim 9, characterized in that the resting periods are equal.
 12. The process as set forth in claim 11, characterized in that the resting periods are of the order of 20 minutes.
 13. The process as set forth in claim 2, characterized in that it includes, after step “e”, the steps of rinsing the load of clothes and spinning the washing liquid. 